This post describes in short how to install the old Cisco VPN client in Windows 10.
DISCLAIMER: I take no responsibility if something of this steps brakes anything. See what you have a recent backup first!.
Step 1
First close all applications.
Step 2
Now run winfix.exe can be found here.
Step 3
Now run the installer for the Dell SonicWall VPN client file found here. (This needs to be installed to get the client to work.)
Step 4
Now install the Cisco VPN client software vpnclient-winx64-msi-5.0.07.0440-k9.exe by unpacking the exe and run vpnclient_setup.msi.
Step 5
Now start regedit as an administrator and go to the below path and locate key:Display Name
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\CVirtA
Change it to below value
Cisco Systems VPN Adapter for 64-bit Windows
Step 6
Now reboot the computer to finish up.
Now all should work fine after this steps. Let me know if something is not working and maybe i can help solv it.